Millionaire developer R. Donahue Peebles is “inching” toward a decision on whether he will run for D.C. mayor next year, his spokeswoman said, but it appears someone is already preparing for him to become a candidate.

The Web domain names Peeblesformayor.com and PeeblesforDC.com, along with several similar-sounding addresses, were registered last month to an unnamed owner, according to a search on the Web domain registration site Whois.com.

When asked about the domain names, Peebles spokesman Kendall Pryles said she could not comment and that Mr. Peebles has not decided whether he will run against Mayor Adrian M. Fenty.

“He’s giving it serious consideration, but he hasn’t made a decision,” Mrs. Pryles said. “It seems like a lot people are excited about the idea.”

She added that Mr. Peebles has been “meeting with people in D.C.” about a possible run.

Mr. Peebles is the owner and CEO of the Peebles Corp., the largest black-owned real estate developer in the country. A native of the District, he was raised by a single mother who worked as a real estate broker and appraiser and also served as a mortgage analyst for Fannie Mae.

One of dozens of guests at President Obama’s job forum at the White House Thursday, Mr. Peebles is often heralded as a business leader and a local success story. He has been listed by Forbes magazine as one of the 10 wealthiest black Americans.

In 1984, then-D.C. Mayor Marion Barry appointed Mr. Peebles as chairman to Washington’s Board of Equalization and Review, a real estate tax appeals board that is now known as the Board of Real Property Assessments and Appeals.

Mr. Peebles, who lately has lived and worked out of Coral Gables, Fla., captured headlines earlier this year when news reports surfaced that he was so dissatisfied with Mr. Fenty’s performance that he pledged to raise $1 million for a credible candidate to challenge the mayor.

A November poll of 501 D.C. voters, conducted by Clarus Research Group, showed 49 percent of voters polled saying they disapprove of Mr. Fenty’s performance and 43 percent saying they approve.

A September poll of 500 voters, conducted by SurveyUSA for WJLA-TV (Channel 7), showed 51 percent of respondents disapproving of Mr. Fenty’s job compared to 40 percent who approve. Fifty-four percent said their opinion of the mayor had gotten worse since he took office.